Self-contamination processes of a spacecraft such as a satellite may be caused by molecules, which outgas from surfaces of the spacecraft in vacuum, particularly from coatings, and are desorbed from the surfaces. Self-contamination may cause adverse changes of the characteristics of the surfaces, for example may degrade the spectral and directional characteristics of optical surfaces or the emissivity, absorptivity, and reflectivity of non-optical surfaces. The publication “Spacecraft outgassing, a largely underestimated phenomen”, M-Hässig et al., 2nd International Conference on Space Technology (ICST), 15-17 Sep. 2011, pages 1-4 Print ISBN: 978-1-4577-1874-8, discusses the problems caused by outgassing and contamination phenomena measured during the Rosetta spacecraft mission.
Since such adverse changes may be critical for space missions, analytical models based on numerical methods have been developed for computing self-contamination processes and determining adverse changes before the launch of a critical space mission. Due to the different materials used in modern spacecraft, self-contamination processes occur in highly different time scales. However, the numerical methods used in the known analytical models for computing self-contamination processes require very long computing times particularly at short time scales and usually produce numerical errors.
The European Space Agency (ESA) provides software called COMOVA (Contamination Modelling Outgassing & Vent Analyses tool) for spacecraft molecular external contamination modelling (Internet: mip.onera.fr/comova/). COMOVA allows the computation of contamination of spacecraft surfaces, but requires relatively long computing times. COMOVA may be also used within ESABASE2 Space Engineering Analysis Tool (Internet: esabase2.net/product/esabase2-comova/) in order to provide computation of contamination deposits on surfaces, including the calculation of view factors and surface temperature effects.